PROJECT SUMMARY Nearly 3.5 million Medicare patients use home health care each year. However, the quality of home health care is highly variable and has been a longstanding concern for US policy. Lower quality home health agencies have poorer rates of compliance with clinical guidelines, poorer functional outcomes, and higher rates of complications among its patients. Thus, Medicare has devoted significant resources toward increasing transparency about the quality of care delivered by health care providers; policymakers hope that providing easy-to-access, simplified quality information would enable patients to choose high quality care, which then incentivizes providers to compete on quality. The home health Quality of Patient Care Star Ratings program, one of several prominent national Star Ratings programs, is Medicare?s flagship initiative to help patients find and choose high-quality home health agencies. It assigns agencies 5-star ratings in half-star increments every quarter. Each rating summarizes an agency?s performance on several quality measures relative to other agencies in the nation. For the program to achieve its goal, it must cause consumers, including patients, families, or formal caregivers who act on behalf of patients, to choose higher rated agencies. A small and growing body of literature suggests that the 5-star format succeeded at eliciting meaningful consumer demand for high-performing providers in the nursing home and health plan sectors. Despite the theoretical benefits of the program and promising findings in other sectors, no research exists on the effectiveness or unintended consequences of the program for home health care. This study is the first to estimate the causal implications of the program on patient admissions and access to care using a regression discontinuity design. This dissertation encompasses three aims: 1) determine whether the program succeeded in shifting patients toward higher rated agencies, 2) examine whether the program affected patient admissions differently depending on the presence of low-quality or potentially fraudulent agencies within a market, and 3) assess whether the program decreased access to higher rated agencies for socially and clinically vulnerable patients. Specifically, I consider whether higher rated agencies leveraged patient demand to their advantage?by increasing admissions of more profitable patients to the detriment of those who are less profitable. The home health population fits squarely with AHRQ?s Priority Populations: compared to the general Medicare population, home health patients are 30 percent more likely to have incomes at or below 200 percent of the Federal Poverty Level, 36 percent more likely to have at least three chronic conditions, and 80 percent more likely to report having fair or poor health. The outcome of this dissertation provides a comprehensive understanding of the effects of the Star Ratings program on patients, which is critical for policy refinement as policymakers grapple with finding solutions to achieve better quality within the US health care system.